1. Field of the Invention
This invention pertains to seat cushions, and, more particularly, to seats having inflatable air bladders that inflate sequentially to promote upward blood flow in the user""s legs while sitting.
2. Description of the Related Art
It is well known that prolonged sitting in a car, on a plane, or in a chair inhibits blood flow from the legs to the heart, resulting in leg discomfort. Constant pressure is applied by the seat to the back of the legs, physically blocking venous flow. Blood begins to pool in the legs which eventually causes discomfort. Intermittent pressure relief for the back of the thighs and buttocks is required to prevent fatigue, skin breakdown, and blood clot formation. Special mechanical and weight limitations often prevent adequate leg movement to relieve such pressure on the thighs.
Heretofore, seat cushions containing inflatable bladders to vary the pressure points on a person""s legs and buttocks have been developed (see U.S. Pat. Nos. 6,098,000, 6,092,249, 6,088,643, 6,088,642, 6,041,784, 5,881,407, 5,687,099, 5,678,891, 5,487,197, 5,379,471, 5,029,939, and 4,840,425). However, none of these seat cushions provide transversely aligned bladders that inflate individually and sequentially from front to back to promote venous blood flow in the legs. Also, none of these seat cushions include features that prevent slippage of the user""s buttocks over the seat when the bladders are inflated.
What is needed is a seat cushion with transversely aligned and sequentially inflated air bladders that apply pressure to the back of the legs to promote venous blood flow in the user""s legs when sitting, and include means to prevent forward movement of the user""s buttocks over the seat during use.
It is an object of the present invention to provide a seat or seat cushion with inflatable bladders that inflate sequentially from front to back to promote venous blood flow in the legs.
It is another object of the present invention to provide such a seat or seat cushion that allows the sequentially inflated bladders to remain inflated for a sufficient amount of time before deflating so that blood is forced upward through the veins.
It is a further object of the present invention to include means to prevent forward movement of the user""s buttocks over the seat during use.
These and other objects of the invention which will become apparent are met by an anti-edema, blood-flow-promoting seat comprising at least three transversely aligned, inflatable air bladders connected to a pump and timer. The bladders are inflated serially and sequentially, from front to back, over a period of approximately eleven seconds and simultaneously deflated to slowly pump blood upward in the legs thereby reducing blood pooling. The cycle is then repeated continuously. Located adjacent to the back air bladder is a transversely aligned, non-inflating seat cushion which continuously supports the user""s ischial tuberocities while sitting to prevent forward movement of the user""s buttocks over the seat while the bladders are inflating and deflating. In the first embodiment, the air bladders extend transversely over the entire width of the seat so that pressure is applied under both legs. In an alternate embodiment offers a split seat option with six inflatable bladders. The six inflatable bladders are divided into two sets of inflatable bladders aligned transversely over one-half of the seat. The user is able to independently control each set of bladders so that all of the bladders in both sets or in each set are constantly inflated, constantly deflated, or sequentially inflated and deflated.